Hydrogen plasma treatment of β -Ga2O3: Changes in electrical properties and deep trap spectra

Abstract

The effects of hydrogen plasma treatment of β-Ga2O3 grown by halide vapor phase epitaxy and doped with Si are reported. Samples subjected to H plasma exposure at 330 °C developed a wide (∼2.5 μm-thick) region near the surface, depleted of electrons at room temperature. The thickness of the layer is in reasonable agreement with the estimated hydrogen penetration depth in β-Ga2O3 based on previous deuterium profiling experiments. Admittance spectroscopy and photoinduced current transient spectroscopy measurements place the Fermi level pinning position in the H treated film near Ec-1.05 eV. Annealing at 450 °C decreased the thickness of the depletion layer to 1.3 μm at room temperature and moved the Fermi level pinning position to Ec-0.8 eV. Further annealing at 550 °C almost restored the starting shallow donor concentration and the spectra of deep traps dominated by Ec-0.8 eV and Ec-1.05 eV observed before hydrogen treatment. It is suggested that hydrogen plasma exposure produces surface damage in the near-surface region and passivates or compensates shallow donors.

Variable temperature probing of minority carrier transport and optical properties in p-Ga2O3

“…Within the current temperature range of measurements, the origin of L decrease is likely due to phonon scattering. 37 Reported values of L for minority carrier (holes) in n-type β-Ga 2 O 3 are within 50-600 nm, 20,21,[38][39][40][41] lower than those of electrons measured in this work for minority carrier electrons. A likely reason could be the large effective mass for holes (18-25 m 0 ).…”

High-Performance Indium Gallium Tin Oxide Transistors with an Al2O3 Gate Insulator Deposited by Atomic Layer Deposition at a Low Temperature of 150 °C: Roles of Hydrogen and Excess Oxygen in the Al2O3 Dielectric Film

“…Indeed, the H and InH concentrations in the IGTO film underneath the ALD-derived Al 2 O 3 film increased when the Al 2 O 3 film was grown under lower P O2 conditions, as shown in Figure b,d, indicating that hydrogen diffuses from the Al 2 O 3 region to the IGTO channel layer during ALD growth of the Al 2 O 3 film and the second PDA at 150 °C. Hydrogen generally affects the electrical properties of transparent conducting oxides (TCOs) such as In 2 O 3 , − Ga 2 O 3 , and SnO 2 , where it gives rise to two forms of shallow donors: interstitial (H i ) and substitutional (H O ) hydrogen donors, leading to n-type doping in TCOs . Similarly, the donor role of incorporated hydrogen has been experimentally observed in multicomponent amorphous indium tin oxide (ITO), indium gallium zinc oxide (IGZO), and indium zinc tin oxide (IZTO), and this is supported by density functional theory (DFT) calculations.…”

Surface zeta potential and diamond growth on gallium oxide single crystal

“…For example, there are well-known challenges for depositing diamond on GaN [38]. Additionally, H 2 plasmas are also known to cause surface damage to β-Ga 2 O 3 [44]. In this work, growth of diamond on β-Ga 2 O 3 substrates has been demonstrated.…”